Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
import java.util.*;
import java.lang.*;
import java.util.Scanner;  
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.io.PrintWriter;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;  
import java.util.Comparator;

public class Solution {

		 
	public static void main(String[] args) {
		
		//FastScanner fs = new FastScanner() ;
		Scanner fs = new Scanner(System.in);
		String a = fs.nextLine();
		
		a = a.replace("{", "");
		a = a.replace("}", "");
		a = a.replaceAll(", ", "");
		a=a.trim();
		Set<Character> s = new LinkedHashSet<>();
		
		for(int i =0;i<a.length();i++) 
			s.add(a.charAt(i));
		
		System.out.println(s.size());
		
		
		
		
		
		//System.out.println(res);
	}
	

		
	
	static int[] sort(int[]x) {
		int [] a = new int[x.length];
		for(int i =0;i<a.length;i++) a[i] = x[i];
		for(int i =0;i<a.length;i++) {
			for(int j=i+1;j<a.length;j++) {
				if(a[i]>a[j]) {
					int temp = a[i];
					a[i] = a[j];
					a[j] = temp;
				}
			}
		}
		return a;
	}
	
	static int[] reverse(int[] input) { 
		int last = input.length - 1;
		int middle = input.length / 2; 
		for (int i = 0; i <= middle; i++)
		{
			int temp = input[i];
			input[i] = input[last - i];
			input[last - i] = temp; 
			}
		return input;
	}

	
	static class FastScanner {
	     BufferedReader reader= new BufferedReader(new InputStreamReader(System.in));
	     StringTokenizer tokenizer = new StringTokenizer("");

	    

	     String next() {
	        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }
	     
	     int[] readArray(int size){
	    	 int [] a  = new int[size];
	    	for(int i =0;i<size;i++) a[i] = a[i]=nextInt();
	    	 return a;
	     }
	     
	     long[] readArrayLong(int size){
	    	 long [] a  = new long[size];
	    	for(int i =0;i<size;i++) a[i] = a[i]=nextInt();
	    	 return a;
	     }

	     long nextLong() {
	        return Long.parseLong(next());
	    }

	     int nextInt() {
	        return Integer.parseInt(next());
	    }
	}
	}